Extended detachable gas distribution plate and showerhead incorporating same

ABSTRACT

Embodiments of showerheads having a detachable gas distribution plate are provided herein. In some embodiments, a showerhead for use in a semiconductor processing chamber may include a body having a first side and a second side; a gas distribution plate disposed proximate the second side of the body and having an annular channel formed in a side surface; and a clamp disposed about a peripheral edge of the gas distribution plate to removably couple the gas distribution plate to the body, wherein the clamp includes a body and a protrusion extending radially inward into the annular groove, and wherein a portion of the gas distribution plate extends over a bottom surface of the clamp.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of co-pending U.S. patent applicationSer. No. 15/416,757, filed Jan. 26, 2017, which claims benefit of U.S.provisional patent application Ser. No. 62/297,930, filed Feb. 21, 2016.Each of the aforementioned patent applications is herein incorporated byreference in their entirety.

FIELD

Embodiments of the present disclosure generally relate to semiconductorprocessing equipment.

BACKGROUND

Conventional detachable showerheads utilized in semiconductor processchambers (e.g., deposition chambers, etch chambers, or the like)typically include a gas distribution plate removably coupled to a bodyusing a metallic (e.g., aluminum) clamp. To prevent sputtering of themetallic clamp material, the clamp is coated with a dielectric (e.g.,quartz). However, the inventors have observed that the coated metallicclamp reduces the size of the gas distribution plate, which acts as anelectrode. In addition, the inventors have further observed that thematerial and location of the clamp can negatively impact etch chemistryand process results for some processes.

Therefore, the inventors have provided embodiments of an improvedshowerhead with a detachable gas distribution plate.

SUMMARY

Embodiments of showerheads having a detachable gas distribution plateare provided herein. In some embodiments, a showerhead for use in asemiconductor processing chamber may include a body having a first sideand a second side; a gas distribution plate disposed proximate thesecond side of the body and having an annular channel formed in a sidesurface; and a clamp disposed about a peripheral edge of the gasdistribution plate to removably couple the gas distribution plate to thebody, wherein the clamp includes a body and a protrusion extendingradially inward into the annular groove, and wherein a portion of thegas distribution plate extends over a bottom surface of the clamp.

In some embodiments a showerhead for use in a semiconductor processingchamber includes: a body having a first side, an opposing second side,and a plurality of through holes to facilitate the passage of processgases through the body; a gas distribution plate disposed proximate thesecond side of the body, having a plurality of gas distribution holesformed through the gas distribution plate from a body-facing side to anopposing processing volume-facing side, and an annular groove formed ina side surface of the gas distribution plate; and a clamp disposed abouta peripheral edge of the gas distribution plate to removably couple thegas distribution plate to the body, wherein the clamp includes a bodyand a protrusion extending radially inward into the annular groove, andwherein a portion of the processing volume-facing side of the gasdistribution plate extends over a predominant portion of a bottomsurface of the clamp.

In some embodiments, a process chamber may include a chamber body havinga substrate support disposed within an inner volume of the chamber body;and a showerhead disposed within the inner volume of the chamber bodyopposite the substrate support. The showerhead includes: a body having afirst side and a second side; a gas distribution plate disposedproximate the second side of the body and having an annular channelformed in a side surface; and a clamp disposed about a peripheral edgeof the gas distribution plate to removably couple the gas distributionplate to the body, wherein the clamp includes a body and a protrusionextending radially inward into the annular groove, and wherein a portionof the gas distribution plate extends over a bottom surface of theclamp.

Other and further embodiments of the present disclosure are describedbelow.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present disclosure, briefly summarized above anddiscussed in greater detail below, can be understood by reference to theillustrative embodiments of the disclosure depicted in the appendeddrawings. However, the appended drawings illustrate only typicalembodiments of the present disclosure and are therefore not to beconsidered limiting of the scope of the disclosure, for the disclosuremay admit to other equally effective embodiments.

FIG. 1 depicts a partial cross-sectional side view of a showerhead witha removable gas distribution plate in accordance with some embodimentsof the present disclosure.

FIG. 1A depicts a partial cross-sectional side view detailing a gasdistribution plate of a showerhead with a removable gas distributionplate in accordance with some embodiments of the present disclosure.

FIG. 1B depicts a partial cross-sectional side view detailing aprotective ring of a showerhead with a removable gas distribution platein accordance with some embodiments of the present disclosure.

FIG. 1C depicts a partial side view detailing a clamp joint of ashowerhead with a removable gas distribution plate in accordance withsome embodiments of the present disclosure.

FIG. 2 depicts a process chamber suitable for use with a showerheadhaving a removable gas distribution plate in accordance with someembodiments of the present disclosure.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. The figures are not drawn to scale and may be simplifiedfor clarity. Elements and features of one embodiment may be beneficiallyincorporated in other embodiments without further recitation.

DETAILED DESCRIPTION

Embodiments of showerheads having a detachable gas distribution plateare provided herein. In at least some embodiments, the inventiveshowerhead may advantageously allow for the removal and replacement ofthe gas distribution plate, thus providing a showerhead having a longeruseful life and a more cost efficient manner of replacing the gasdistribution plate as compared to conventional showerheads having apermanently bonded gas distribution plate.

FIG. 1 depicts a showerhead with a gas distribution plate in accordancewith some embodiments of the present disclosure. The showerhead 100generally comprises a body 102, a gas distribution plate 104 and a clamp110 configured to removably couple the gas distribution plate to thebody 102.

The body 102 comprises a first side 150, a second side 140 and aplurality of through holes 116 formed in the body 102 extending from thefirst side 150 to the second side 140. The plurality of through holes116 facilitate the passage of process gases through the body 102 to thegas distribution plate 104. In some embodiments, the through holes 116may be counter sunk (e.g., countersink 118 shown) to reduce a residualelectrical field at the through holes 116 and to facilitate a moreuniform gas flow to the gas distribution plate 104. In some embodiments,a cavity 114 may be formed in first side 150 of the body 102 tofacilitate more even distribution of process gases to the plurality ofthrough holes 116. The body 102 may be fabricated from any suitableprocess compatible material, for example, such as aluminum. Byfabricating the body 102 from a conductive material such as aluminum,the body 102 may function as an electrode to facilitate, for example,the formation of a plasma from process gases provided to the showerhead100.

In some embodiments, one or more channels may be formed in the surfacesof the body 102 to accommodate one or more o-rings and/or RF gaskets(o-rings 130, 132, 134 and RF gaskets 108, 126 shown). When present, theo-rings 130, 132, 134 provide a seal between the body 102 and clamp 110or surfaces of the process chamber (not shown). The o-rings 130, 132,134 may be fabricated from any material suitable to facilitate theaforementioned seal, for example, rubber.

The RF gaskets 108, 126 facilitate conductivity of RF power from, forexample, an RF source to the body 102 and the clamp 110. For example, RFpower may be provided from an RF power supply (such as the RF powersupply 248 described below) to a component coupled to the body 102 andin contact with one or more RF gaskets (e.g., RF gasket 126). Thelocation of the o-rings and the RF gaskets are illustrative only.Additional or alternate positions of one or more of the o-rings and theRF gaskets may be used. In some embodiments, an RF gasket 109 may beprovided between the clamp 110 and the gas distribution plate 104, asdepicted in FIG. 1A. Positioning the RF gasket 109 along the innerdiameter of the clamp 110 (above the protrusion 154) advantageouslyfacilitates RF return and enhances the gas distribution plate 104electrode area in the plasma. The RF gaskets 108, 109, 126 may befabricated from any suitable conductive material, for example stainlesssteel.

The gas distribution plate 104 facilitates distribution of process gasesprovided from the body 102 to, for example, a processing volume of aprocess chamber via a plurality of gas distribution holes 142 formed inthe gas distribution plate 104. The gas distribution holes 142 may bearranged in any manner suitable to provide a desired distribution ofprocess gases. For example, in some embodiments, the gas distributionholes 142 may be arranged in clusters disposed about the through holes116 of the body 102 when the gas distribution plate 104 is coupled tothe body 102.

The gas distribution plate 104 includes an annular groove 152 formed ina side surface 153 of the gas distribution plate 104. The annular groove152 is sized to accommodate a portion of the clamp 110 as discussedbelow. The gas distribution plate 104 also includes a lower portion 156that extends over a bottom surface of the clamp 110 to increase the sizeof the exposed portion of the gas distribution plate. In someembodiments, the lower portion 156 extends over substantially the entirebottom surface of the clamp 110. The inventors have observed that theincreased exposed surface area of the gas distribution plate 104advantageously improves the electrical field because more RF powercouples to a plasma formed beneath the gas distribution plate 104 due tothe increased surface area. As a result, edge uniformity of a substratebeing processed is advantageously improved due to the increased plasmauniformity at the edge of the substrate. In addition, the increasedexposed surface area of the gas distribution plate 104 facilitateslocation of additional gas distribution holes 142 further radiallyoutward, which has also been found to advantageously improve edgeuniformity of a substrate being processed.

The gas distribution plate 104 may be fabricated from any materialsuitable to resist degradation during exposure to a plasma (e.g., aplasma formed in a process chamber during processing). For example insome embodiments, the gas distribution plate 104 may be fabricated fromsingle crystalline silicon (Si). Single crystalline silicon is nottypically used as a material for the gas distribution plate at least inpart due to single crystalline silicon having a faster etch rate ascompared to silicon carbide, a favored material. However, the inventorshave observed that single crystalline silicon is less susceptible tosurface roughness change, arcing, and micro-masking, and furtherprovides better operability at elevated temperatures (e.g., higher thanabout 150 degrees Celsius) as compared to conventional materialsutilized to fabricate gas distribution plates, for example, such assilicon carbide (SiC). In addition, single crystal silicon is morereadily available and obtainable at a lower cost as compared to theconventional materials. In addition, in embodiments where the showerhead100 is used in substrate processes involving silicon-containing gases,fabricating the gas distribution plate 104 from silicon reduces theinstances of contamination due to degradation of the gas distributionplate 104.

The gas distribution plate 104 may have any suitable thicknesssufficient to provide a desired gas distribution and suitable usefulfunctional life. In addition, in some embodiments, the gas distributionplate 104 may have a suitable thickness sufficient to ensure continuouscontact with one or more thermal gaskets (three thermal gaskets 120,122, 124 shown) disposed between the gas distribution plate 104 and thebody 102 when the gas distribution plate 104 is coupled to the body 102.For example, in some embodiments, the thickness of the gas distributionplate 104 may be selected such that an amount of bowing of the gasdistribution plate 104 caused by the forces provided by the clamp 110 atthe edge of the gas distribution plate 104 is less than an amount ofdeformation of the thermal gaskets 120, 122, 124 when compressed, thusensuring continuous contact with the thermal gaskets 120, 122, 124 whenclamped. Alternatively, or in combination, in some embodiments, thethickness of the gas distribution plate 104 may be selected to providean aspect ratio of the gas distribution holes 142 suitable to reduceplasma penetration and improve the useful functional life of the gasdistribution plate 104. For example, in embodiments where the gasdistribution holes 142 have a diameter of about 0.5 mm, the gasdistribution plate 104 may have a thickness of about 11.1 mm. In someembodiments, the aspect ratio of the gas distribution holes 142 is about22:1.

The clamp 110 facilitates coupling the gas distribution plate 104 to thebody 102. In some embodiments, the clamp 110 facilities such couplingvia a fastener 106 provided to a through hole 136 formed in the body 102corresponding to a threaded hole 138 formed in the clamp. The clamp 110may be fabricated from any process compatible conductive material, forexample aluminum.

As noted above, conventional clamps which clamp the gas distributionplate on a substrate-facing surface limit the size of an exposedsubstrate-facing surface and must also be coated with a dielectric sothat the metallic clamp material is not sputtered. As such, theinventors have developed the inventive showerhead having the gasdistribution plate 104 described above. The clamp 110 is formed of twoor more arcuate pieces (e.g., 110A, 110B, depicted in FIG. 1C) that formthe annular structure of the clamp 110. In some embodiments, the clamp110 is formed of two semicircular pieces. In some embodiments, and asdepicted in FIG. 1C, the separate pieces of the clamp 110 may have anon-linear joint (e.g., non-linear mating edges), such as the lap jointbetween adjacent clamp pieces 110A and 110B depicted in FIG. 1C, thatadvantageously prevents a line of sight gap from one side of the clampto the opposite side of the clamp that may undesirably allow plasmaignition in and/or through the gap.

The clamp 110 includes a body 155 and a protrusion 154 extendingradially inward from the body 155. When the showerhead 100 is assembled,the protrusion 154 extends into the annular groove 152 and, thus,couples the gas distribution plate 104 to the body 102. To ensurecorrect alignment of the gas distribution plate 104 with the pluralityof through holes 116, each piece of the two or more arcuate pieces ofthe clamp 110 includes one or more pins 162 extending perpendicularly toan upper surface 161 of the protrusion 154. One or more correspondingslots 163 (one shown) are formed in the gas distribution plate 104 toaccommodate a corresponding pin 162. In some embodiments, to furtherensure correct alignment of the gas distribution plate 104 with theplurality of through holes 116, each pin 162 may be sized differentlythan the other pins. In such embodiments, each slot 163 is sized toaccommodate only one of the pins 162 so that the gas distribution plate104 has one position (or orientation) in which the pins 162 fit intotheir corresponding slots 163.

In some embodiments, the clamp 110 may include one or more channelsformed in surfaces of the clamp 110 to accommodate one or more o-rings(o-ring 128 shown). When present, the o-ring 128 provides cushioning tothe gas distribution plate 104 to prevent breakage of the gasdistribution plate 104 when clamped to the body 102. Providing the RFcurrent path to the gas distribution plate 104 also shields a gap 146between the body 102 and the gas distribution plate 104, which reducesarcing, for example, at the through holes 116 of the body 102. Theo-ring 128 may be fabricated from any suitable material, for examplesuch as the materials discussed above with respect to the o-rings 130,132, 134. The o-ring 128 spaces the gas distribution plate 104 apartfrom the clamp 110.

In some embodiments, the thermal gaskets 120, 122, 124 may be disposedbetween the body 102 and gas distribution plate 104. When present, thethermal gaskets 120, 122, 124 may facilitate a heat exchange between thebody 102 and the gas distribution plate 104, for example, to provide amore uniform thermal gradient across the gas distribution plate 104. Inaddition, the thermal gaskets 120, 122, 124 may provide the gap 146between the body 102 and the gas distribution plate 104 and defineseparate plenums (e.g., zones) for groups of through holes 116 andcorresponding gas distribution holes 142. The inventors have discoveredthat by minimizing the gap 146, plasma light-up between the gasdistribution plate 104 and the body 102 may be prevented at high power.In some embodiments, the gap 146 may be between about 0.1 mm to about0.5 mm to eliminate plasma light-up at a bias power level between about10 kW to about 15 kW and source power greater than about 2,500 W.

The thermal gaskets 120, 122, 124 may be fabricated from anycompressible, thermally conductive material having low out-gassing atprocess pressures and temperatures (e.g., vacuum conditions andtemperatures at or above about 150 degrees Celsius). For example, insome embodiments, the gasket may comprise a silicon containing material.The thermal gaskets 120, 122, 124 may have any shape suitable tomaintain contact between the body 102 and the gas distribution plate104. For example, in some embodiments, the thermal gaskets 120, 122, 124may be a plurality of concentric rings having a rectangular crosssection as shown in FIG. 1. In some embodiments, the geometry of thethermal gaskets 120, 122, 124 may be optimized to accommodate for adifference in distance between the body 102 and the gas distributionplate 104 when clamped together due to the forces provided by the clamp110 at the edge of the gas distribution plate 104 (e.g., bowing of thegas distribution plate 104).

In some embodiments, a protective ring 112 may be disposed about theshowerhead to shield portions of the body 102, clamp 110 and gasdistribution plate 104. The protective ring 112 may be fabricated fromany suitable process compatible material, for example, quartz (SiO₂).Conventionally, the protective ring 112 extends over the bottom surfaceof the clamp to protect the clamp from being sputtered by the plasma.However, because the lower portion 156 of the inventive gas distributionplate 104 extends over the bottom surface of the clamp 110, in someembodiments, the protective ring 112 extends only up to the periphery ofthe lower portion 156 and does not extend over the substrate-facingsurface of the gas distribution plate 104. As a result, a larger surfacearea of the gas distribution plate 104 is advantageously exposed to aplasma formed beneath the gas distribution plate 104, thus improvingplasma uniformity, especially at an edge of a substrate being processed.Alternatively, in some embodiments, a small portion of the edge of thegas distribution plate 104 may be covered by an end portion 113 of theprotective ring 112, as depicted in FIG. 1B. In such configurations, alarger surface area of the gas distribution plate 104 is stilladvantageously exposed to a plasma formed beneath the gas distributionplate 104 (as compared to conventional designs), thus improving plasmauniformity, especially at an edge of a substrate being processed, whileimparting additional protection to the edge of the gas distributionplate 104.

In some embodiments, the showerhead 100 may include a plurality of hardstops 170 (one hard stop 170 shown in FIG. 1) disposed about a centralaxis of the showerhead in a corresponding plurality of holes 172 (onehole 172 shown in FIG. 1) to provide a more rigid support for spacingthe gas distribution plate 104 apart from the body 102. Each hard stop170 may include a through hole to allow gas trapped in the hole 172 toescape. The plurality of hard stops may be formed of any rigid processcompatible polyamides. The plurality of hard stops 170 prevent overcompression of the thermal gaskets 120, 122, 124.

FIG. 2 depicts a schematic view of an illustrative process chamber 200suitable for use with a showerhead in accordance with some embodimentsof the present disclosure. Exemplary process chambers may include theENABLER®, ENABLER® E5, ADVANTEDGE™, or other process chambers, availablefrom Applied Materials, Inc. of Santa Clara, Calif. Other suitableprocess chambers having, or being modified to have, showerheads maysimilarly benefit from the present disclosure.

In some embodiments, the process chamber 200 may generally comprise achamber body 202 having a substrate support pedestal 208 for supportinga substrate 210 thereupon disposed within an inner volume 205 of thechamber body, and an exhaust system 220 for removing excess processgases, processing by-products, or the like, from the inner volume 205 ofthe chamber body 202.

In some embodiments, an upper liner 264 and a lower liner 266 may coverthe interior of the chamber body 202 to protect the chamber body 202during processing. In some embodiments, the chamber body 202 has aninner volume 205 that may include a processing volume 204. Theprocessing volume 204 may be defined, for example, between the substratesupport pedestal 208 and a showerhead 214 (e.g., showerhead 100described above) and/or nozzles provided at desired locations. In someembodiments, a gas supply 288 may provide one or more process gases tothe showerhead 214 for distribution of the one or more process gases tothe processing volume 204 of the chamber body 202.

In some embodiments, the substrate support pedestal 208 may include amechanism that retains or supports the substrate 210 on the surface ofthe substrate support pedestal 208, such as an electrostatic chuck, avacuum chuck, a substrate retaining clamp, or the like. Alternatively,or in combination, in some embodiments, the substrate support pedestal208 may include mechanisms for controlling the substrate temperature(such as heating and/or cooling devices, not shown) and/or forcontrolling the species flux and/or ion energy proximate the substratesurface. For example, in some embodiments, the substrate supportpedestal 208 may include an electrode 240 and one or more power sources(two bias power sources 238, 244) coupled to the electrode 240 viarespective matching networks 236, 262. For example, the substratesupport pedestal 208 may be configured as a cathode coupled to a biaspower source 244 via a matching network 262. The above described biaspower sources (e.g., bias power sources 238, 244) may be capable ofproducing up to 12,000 W at a frequency of about 2 MHz, or about 13.56MHz, or about 60 MHz. The at least one bias power source may provideeither continuous or pulsed power. In some embodiments, the bias powersource alternatively may be a DC or pulsed DC source.

In some embodiments, the substrate support pedestal 208 may include asubstrate support ring 280 disposed atop the substrate support pedestal208 and configured to support at least a portion of the substrate 210during processing. In some embodiments, one or more rings (insert ring278 and barrier ring 242 shown) may be disposed about the substratesupport pedestal 208. The one or more rings may be fabricated from anysuitable process compatible material. For example, in some embodiments,the insert ring may be fabricated from silicon (Si). In someembodiments, the barrier ring 242 may be fabricated from quartz (SiO₂).In some embodiments, a grounded mesh 260 may be disposed about theperiphery of the substrate support pedestal 208 and coupled to thechamber body 202.

The substrate 210 may enter the chamber body 202 via an opening 212 in awall of the chamber body 202. The opening 212 may be selectively sealedvia a slit valve 218, or other mechanism for selectively providingaccess to the interior of the chamber through the opening 212. Thesubstrate support pedestal 208 may be coupled to a lift mechanism 234that may control the position of the substrate support pedestal 208between a lower position (as shown) suitable for transferring substratesinto and out of the chamber via the opening 212 and a selectable upperposition suitable for processing. The process position may be selectedto maximize process uniformity for a particular process. When in atleast one of the elevated processing positions, the substrate supportpedestal 208 may be disposed above the opening 212 to provide asymmetrical processing region.

In some embodiments, a protective ring 206 (e.g., the protective ring112 described above) may be disposed about, and covering at least aportion of, the showerhead 214, for example, such as the body 294 (e.g.,body 102 described above) or the gas distribution plate 296 (e.g., thegas distribution plate 104 described above) of the showerhead 214. Insome embodiments, the protective ring 206 may be supported by the upperliner 264. In some embodiments, a substrate facing surface of theprotective ring 206 may be flush with or extend up to about 2 mm beyonda substrate facing surface of the gas distribution plate 296 toeliminate any line of sight between the gas distribution plate 296 andthe upper liner 264, which may be grounded.

In some embodiments, the showerhead 214 may be coupled to and/orsupported by, a chiller plate 284. When present, the chiller plate 284facilitates control over a temperature of the showerhead 214 duringprocessing. In some embodiments, the chiller plate 284 comprises aplurality of channels (not shown) formed in the chiller plate 284 toallow a temperature control fluid provided by a temperature controlfluid supply (chiller) 290 to flow through the chiller plate 284 tofacilitate the control over the temperature of the showerhead 214. Thechiller plate 284 is coupled to the showerhead 214 via the body 294. Insome embodiments, the body 294 may include a plurality of ribs toimprove thermal coupling between the body 294 and the chiller plate 284.

In some embodiments, one or more coils (inner coil 274 and outer coil272 shown) may be disposed above and/or proximate a peripheral edge ofthe showerhead 214. When present, the one or more coils may facilitateshaping a plasma formed within the processing volume 204 of the processchamber 200.

In some embodiments, an RF power source 286 provides RF power to thechiller plate 270 and/or the showerhead 214 via a coaxial stub 292. Thecoaxial stub 292 is a fixed impedance matching network having acharacteristic impedance, resonance frequency, and provides anapproximate impedance match between the showerhead 214 and the RF powersource 286. In some embodiments, the coaxial stub 292 generallycomprises an inner cylindrical conductor 298, an outer cylindricalconductor 201 and an insulator 203 filling the space between the innercylindrical conductor 298 and the outer cylindrical conductor 201.

The inner cylindrical conductor 298 and the outer cylindrical conductor201 may be constructive of any suitable conductive material capable ofwithstanding the particular process environment. For example, in someembodiments, the inner cylindrical conductor 298 and the outercylindrical conductor 201 may be fabricated from nickel-coated aluminum.One or more taps 221 are provided at particular points along the axiallength of the coaxial stub 292 for applying RF power from the RF powersource 286 to the coaxial stub 292. An RF power terminal 207 and the RFreturn terminal 209 of the RF power source 286 are connected at the tap221 on the coaxial stub 292 to the inner cylindrical conductor 298 andthe outer cylindrical conductor 201, respectively. A terminatingconductor 211 at the far end 213 of the coaxial stub 292 shorts theinner cylindrical conductor 298 and the outer cylindrical conductor 201together, so that the coaxial stub 292 is shorted at a far end 213 ofthe coaxial stub 292. At the near end 215 of the coaxial stub 292, theouter cylindrical conductor 201 is connected to the chamber body 202 viaan annular conductive housing or support 276, while the innercylindrical conductor 298 is connected to the chiller plate 270 and/orshowerhead 214 via a conductive cylinder 217. In some embodiments, adielectric ring 219, is disposed between and separates the conductivecylinder 217 and the chiller plate 270.

The exhaust system 220 generally includes a pumping plenum 224 and oneor more conduits that couple the pumping plenum 224 to the inner volume205 (and generally, the processing volume 204) of the chamber body 202,for example via one or more inlets 222. A vacuum pump 228 may be coupledto the pumping plenum 224 via a pumping port 226 for pumping out theexhaust gases from the chamber body 202. The vacuum pump 228 may befluidly coupled to an exhaust outlet 232 for routing the exhaust asneeded to appropriate exhaust handling equipment. A valve 230 (such as agate valve, or the like) may be disposed in the pumping plenum 224 tofacilitate control of the flow rate of the exhaust gases in combinationwith the operation of the vacuum pump 228. Although a z-motion gatevalve is shown, any suitable, process compatible valve for controllingthe flow of the exhaust may be utilized.

To facilitate control of the process chamber 200 as described above, thecontroller 250 may be any form of general-purpose computer processorthat can be used in an industrial setting for controlling variouschambers and sub-processors. The memory, or computer-readable medium,256 of the CPU 252 may be one or more of readily available memory suchas random access memory (RAM), read only memory (ROM), floppy disk, harddisk, or any other form of digital storage, local or remote. The supportcircuits 254 are coupled to the CPU 252 for supporting the processor ina conventional manner. These circuits include cache, power supplies,clock circuits, input/output circuitry and subsystems, and the like. Oneor more methods and/or processes may generally be stored in the memory256 as a software routine 258 that, when executed by the CPU 252, causesthe process chamber 200 to perform the processes methods and/orprocesses.

Thus, embodiments of a showerhead having a detachable gas distributionplate have been provided herein. Embodiments of the inventive showerheadmay advantageously provide a longer useful life and a more costefficient manner of replacing the gas distribution plate, as well asimproved processing results, as compared to conventional showerheads.

While the foregoing is directed to embodiments of the presentdisclosure, other and further embodiments of the disclosure may bedevised without departing from the basic scope thereof.

The invention claimed is:
 1. A gas distribution plate for use in asemiconductor processing chamber, comprising: a plate having an upperportion having a first side and a lower portion having an opposingprocessing volume-facing side, wherein the lower portion extendsradially outward beyond the upper portion; an annular groove formed in aside surface of the gas distribution plate between the upper portion andthe lower portion, wherein an upper surface of the annular grooveincludes a step; and a plurality of gas distribution holes formedthrough the plate from the first side to the processing volume-facingside, and wherein the upper surface of the annular groove is oppositeand parallel to a lower surface of the annular groove.
 2. The gasdistribution plate of claim 1, wherein the plate is fabricated fromsingle crystalline silicon (Si).
 3. The gas distribution plate of claim1, further comprising one or more slots formed in the plate toaccommodate one or more corresponding pins.
 4. The gas distributionplate of claim 3, wherein each of the one or more slots are sizeddifferently.
 5. The gas distribution plate of claim 1, wherein athickness of the lower portion is less than a thickness of the upperportion.
 6. The gas distribution plate of claim 1, wherein a width ofthe annular groove is greater than a thickness of the lower portion. 7.The gas distribution plate of claim 1, wherein a bottom of the annulargroove is closer to a nearest gas distribution hole of the plurality ofgas distribution holes than to an outer sidewall of the lower portion.8. The gas distribution plate of claim 1, wherein the gas distributionholes are arranged in clusters.
 9. A showerhead for use in asemiconductor processing chamber, comprising: a gas distribution platehaving an upper portion and a lower portion, wherein the lower portiondefines an outermost diameter of the gas distribution plate; and anannular groove formed in a side surface of the gas distribution platebetween the upper portion and the lower portion, wherein the upperportion and the lower portion extend parallel to each other radiallyoutward from an inner surface of the annular groove, and wherein anupper surface of the annular groove and a lower surface of the annulargroove extend parallel to each other radially outward from the innersurface.
 10. The showerhead of claim 9, wherein the gas distributionplate is fabricated from single crystalline silicon (Si).
 11. Theshowerhead of claim 9, wherein a plurality of gas distribution holes areformed through the gas distribution plate.
 12. The showerhead of claim11, wherein the plurality of gas distribution holes are arranged inclusters within concentric rings.
 13. The showerhead of claim 9, furthercomprising: a body disposed proximate the upper portion of the gasdistribution plate; and a clamp disposed about a peripheral edge of thegas distribution plate to clamp the gas distribution plate to the body,wherein the clamp includes a protrusion extending radially inward intothe annular groove, and wherein a portion of the gas distribution plateextends over a bottom surface of the clamp.
 14. The showerhead of claim13, wherein the clamp comprises two or more arcuate pieces or twosemicircular pieces.
 15. The showerhead of claim 13, wherein the portionof the gas distribution plate substantially completely covers the bottomsurface of the clamp.
 16. The showerhead of claim 13, further comprisingan RF gasket disposed between the clamp and the gas distribution plate.17. The showerhead of claim 13, wherein the body includes a plurality ofthrough holes formed through the body.
 18. The showerhead of claim 13,further comprising a thermal gasket, wherein the thermal gasketcomprises a plurality of concentric rings disposed between the body andthe gas distribution plate.
 19. A process chamber, comprising: a chamberbody having a substrate support disposed within an inner volume of thechamber body; and a showerhead disposed within the inner volume of thechamber body opposite the substrate support, wherein the showerhead isas described in claim 9.